X0304 4 2012-02-28 0 0001316835 Builders FirstSource, Inc. BLDR 0001332737 Warburg Pincus Private Equity IX, L.P. C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001342445 Warburg Pincus IX LLC C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001322709 Warburg Pincus Partners LLC C/O WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0000929408 WARBURG PINCUS & CO. 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001162870 WARBURG PINCUS LLC 450 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001239318 KAYE CHARLES R C/O WARBURG PINCUS LLC 450 LEXINGTON AVE NEW YORK NY 10017 0 0 1 0 0001220638 Landy Joseph P. C/O WARBURG PINCUS LLC 450 LEXINGTON AVE NEW YORK NY 10017 0 0 1 0 Common Stock, par value $0.01 per share ("Common Stock") 2012-02-28 4 P 0 19000 3.15 A 24466425 D Common Stock 2012-02-29 4 P 0 47100 3.10 A 24513525 D Common Stock 2012-03-01 4 P 0 34006 3.09 A 24547531 D See Exhibit 99.1, note (1) See Exhibit 99.1, note (2) See Exhibit 99.1, note (3) See Exhibit 99.1, note (4) See Exhibit 99.1, note (5) See Exhibit 99.1, note (6) Exhibit List: Exhibit 99.1 - Explanation of Responses Exhibit 99.2 - Joint Filers' Names and Addresses Exhibit 99.3 - Joint Filers' Signatures WARBURG PINCUS PIVATE EQUITY IX, L.P., By: Warburg Pincus IX LLC, its General Partner, By: Warburg Pincus Partners LLC, its Sole Member, By: Warburg Pincus & Co., its Managing Member, By: /s/ Scott A. Arenare, Partner 2012-03-01